Biomarkers for Measuring HIV Incidence in Populations: Statistical Issues

• Activity Number: 442
• Type: Invited
• Date/Time: Wednesday, August 1, 2012 : 8:30 AM to 10:20 AM
• Sponsor: Biometrics Section
• Author(s): Ron Brookmeyer*+
• Companies: University of California at Los Angeles
• Keywords: biomarkers ; HIV/AIDS ; epidemics ; incidence ; accuracy

Abstract

The development of accurate methods for measuring the spread of the HIV epidemic has been a continuing public health challenge since the beginning of the AIDS epidemic. HIV incidence is the rate new infections occur in populations. Progress has been made in using biomarkers in cross-sectional samples to determine HIV incidence. The approach has been used throughout the world; however, controversy has ensued about its accuracy, and how to measure statistical accuracy. We outline a framework for evaluating the accuracy of biomarkers for determining HIV incidence, and contrast it with traditional measures of diagnostic test accuracy. We introduce a quantity, the shadow, for comparing the accuracy of various biomarkers for HIV incidence estimation, which depends on the tail behavior of the distribution of durations a biomarker classifies an HIV infected person as a recent infection. We discuss several biomarkers in use for HIV incidence determination including assays for BED, avidity, antigen, viral loads, and CD4 T cell counts. We discuss how multiple biomarkers can be combined to increase the accuracy of HIV incidence to track the spread of the AIDS epidemic.